Transendothelial migration (TEM) of Th1 and Th17 cells across the blood-brain barrier (BBB) has a critical role in the development of experimental autoimmune encephalomyelitis (EAE). How cytokines produced by inflammatory Th1 and Th17 cells damage the endothelial BBB and promote transendothelial migration of immune cells into the central nervous system (CNS) during autoimmunity is not understood. We therefore investigated the effect of various cytokines on brain endothelial cells. Among the various cytokines tested, such as Th1 (IFN-γ, IL-1α, IL-1β, TNF-α, IL-12), Th2 (IL-3, IL-4, IL-6 and IL-13), Th17 (IL-17A, IL-17F, IL-21, IL-22, IL-23, GM-CSF) and Treg-specific cytokines (IL-10 and TGF-β), IFN-γ predominantly showed increased expression of ICAM-1, VCAM-1, MAdCAM-1, H2-K and I-A molecules on brain endothelial cells. Furthermore, IFN-γ induced transendothelial migration of CD4 T cells from the apical (luminal side) to the basal side (abluminal side) of the endothelial monolayer to chemokine CCL21 in a STAT-1-dependent manner. IFN-γ also favored the transcellular route of TEM of CD4 T cells. Multicolor immunofluorescence and confocal microscopic analysis showed that IFN-γ induced relocalization of ICAM-1, PECAM-1, ZO-1 and VE-cadherin in the endothelial cells, which affected the migration of CD4 T cells. These findings reveal that the IFN-γ produced during inflammation could contribute towards disrupting the BBB and promoting TEM of CD4 T cells. Our findings also indicate that strategies that interfere with the activation of CNS endothelial cells may help in controlling neuroinflammation and autoimmunity.
Natural biotic communities from Kalbadevi Bay were monitored in microcosms (1-l glass flasks) to test the hypothesis that iron released from ilmenite through microbial action contributes to proliferation of phytoplankton. Microcosms containing ilmenite had significantly higher phytoplankton growth compared with controls containing no ilmenite or those containing only ferrous sulfate. Phytoplankton cell numbers in the ilmenite-supplemented treatment were 20= higher than in controls. The later stages were marked by the dominance of bottom dwelling Nitzschia spp. and Navicula spp. Iron-preferring Eunotia spp. and Pinnularia spp. were also encountered. Hence, increased phytoplankton biomass may be attributable to the steady release of bioavailable iron. We therefore infer that ilmenite mineral might sustain the phytoplankton community in ilmenite-dominated systems. Increases in density and diversity of phytoplankton over time and significant interrelationship between various parameters in the microcosm containing ilmenite indicate that stimulatory effect of iron released from this mineral could be beneficial to the biota in the system.
This lead exposure study was conducted in a total of 452 school children in the age group of 9–14 years. Two hundred and ninety-eight exposed children came from the villages situated within a 2.5 km radius of the lead–zinc mine whereas the comparative group children were selected from the villages at least 10 km away from mine. Environmental monitoring study suggested that lead levels in air and water samples near the mining areas were within the Central Pollution Control Board prescribed standards. Lead levels in about 80% of the children were less than 10 μg/dl. Medical examination of all children did not show any signs related to lead toxicity but central nervous system-related symptoms, as reported by the subjects during medical examination, were found to be higher in the exposed group when compared with the comparative group. The values of physical growth parameters of the exposed group were comparable with that of the comparative group for both girls and boys. Hence, the physical growth of children was found to be unaffected by the observed level of lead exposure. To safeguard the health of the children residing near the mining area, various preventive and control measures were suggested.
The coastal waters of Goa and Ratnagiri lying on the West coast of India are influenced by terrestrial influx. However, Goa is influenced anthropogenically by iron-ore mining, while Ratnagiri is influenced by deposition of heavy minerals containing iron brought from the hinterlands. We hypothesize that there could be a shift in biological response along with changes in network of interactions between environmental and biological variables in these mining and non-mining impacted regions, lying 160 nmi apart. Biological and environmental parameters were analyzed during pre-monsoon season. Except silicates, the measured parameters were higher at Goa and related significantly, suggesting bacteria centric, detritus-driven region. At Ratnagiri, phytoplankton biomass related positively with silicate suggesting a region dominated by primary producers. This dominance perhaps got reflected as a higher tertiary yield. Thus, even though the regions are geographically proximate, the different biological response could be attributed to the differences in the web of interactions between the measured variables.
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